Amine oxides are used in many commercial products, such as laundry detergents, fabric softeners, and shampoos. They provide benefits such as softness, hand mildness and suds generation.
Traditional techniques for making amine oxide have utilized batch processes and result in aqueous compositions comprising approximately 30% by weight of the aqueous composition of amine oxide. Thus, in order to achieve required levels of amine oxide in final commercial products, large quantities of aqueous amine oxide compositions need to be added.
The addition of large quantities of these aqueous amine oxide compositions results in the addition of large quantities of water. This has the negative effect of reducing the formulation freedom of the final commercial product due to the presence of the water. Furthermore, the presence of large quantities of water in the aqueous amine oxide composition results in transportation inefficiency since large quantities of water need to be transported resulting in increased costs.
It is desirable to develop a process to manufacture amine oxide compositions comprising at least 65% by weight of amine oxide. However, there is a general reluctance in the field to achieve this due to the very long reaction times needed to make amine oxide compositions. Commercial scale batch processes used today to make 30% by weight amine oxide compositions can take up to 8 hours to complete. Thus the expectation is that it would take even longer to manufacture an at least 65% amine oxide composition. Furthermore, the amine oxide present in a composition comprising at least 65% by weight amine oxide would mostly exist in the lamellar phase. To arrive at the lamellar phase, the amine oxide composition would firstly need to pass through the hexaganol phase which results in highly viscous amine oxide compositions. This is very difficult to handle during manufacture.
Thus there is a need in the art for a process capable of producing an amine oxide composition comprising concentrations of at least 65% amine oxide so minimizing the amount of water present. It is also desirable to develop a continuous process in which at least 65 wt % amine oxide compositions can be efficiently and quickly produced.
It was surprisingly found that the process of the present invention solved the above mentioned problems.